Mining machine rotary cutter bar



Nov. 5, 1968 Filed Jan. 5, 1968 Fig.1

c. B. KREKELER 3,409,331

MINING MACHINE ROTARY CUTTER BAR 5 Sheets-Sheet 1 INVENTOR CLAUDEBKEE/(ELER,

BY y m LVW and Z2,

' ATTORN EYS" Nov. 5, 1968 c. B. KREKELER 3,409,331

MINING MACHINE ROTARY CUTTER BAR Filed Jan. 5, 1968 5 Sheets-Sheet 2 65INVENTOR cmuommmm,

BY flwm aw. Mid

ATTORNEYS C. B. KREKELER MINING MACHINE ROTARY CUTTER BAR Nov. 5, 1968 5Sheets-Sheet 3 Filed Jan. 5, 1968 INVENTOR/S 04 4005 8. KQEKEL 5/2,

ATTORN EYS M ddm, 90 4;, M

United States Patent Oflice I 'ABSTRACT OF THE DISCLOSURE Arotary cutterbar for a continuous mining machine or the like, which comprises atleast one elongated body member providing a plurality of spaced surfacesextending the length thereof. A plurality of lugs are located betweenand aflixed to adjacent ones ofthe spaced surfaces, and are adapted toreceive the shanks of cutter bits.

CROSS REFERENCE TO RELATED APPLICATIONS This is a continuation-in-partof the copending application of the same inventor, Ser. No. 555,140,filed June 3, 1966, now abandoned and entitled, Improvements inContinuous Mining Machines.

BACKGROUND OF THE INVENTION (1) Fieldof invention This invention relatesto improvements in continuous mining machines and more particularly toimprovements in rotary cutter bars therefor.

(2) Description of the prior art Wherever 'possible, present day coalmining operations make use of self-propelled continuous mining machines.Boring type continuous mining machines generally perform the steps ofcutting into the face of a coal seam, thereby making their ownpassageway, and loading the coal on conveyor means. The most frequentlyencountered machines of this type have a plurality of interdigitatingrotary cutter arms which make a cut in the form of two or moreoverlapping circles in side-by-side relationship. These machines arealso provided with cutting means mounted behind the rotary cutter armsand which make an upper and lower cuttransforming the two or moreoverlapping side-by-side circular cuts into one larger cut of generallyoval configuration. The elongated portions of the oval cut form the roofand the floor of the mine entry.

The cutting means behind the rotary cutter arms has usually taken theformof a continuous cutter chain provided with cutter bits and socketmembers therefor. The continuous cutter chain or trim chain passes abouta series of sprockets in such a way that there are upper and lowerflights of the chain which make the above mentioned upper and lowercuts.

A trim chain of the type described has a number of disadvantages. Such atrim chain is made up of a plurality of part's'and is subject tobreakage.'Under some circumstances excessive packing of coal cuttingsand foreign material may occur about the sprocket wheels. Often thispacking can be sufficiently severe to cause the trim chain to bedisengaged from the sprocket teeth, or to produce breakage in theapparatus.

In recent years, continuous boring-type mining machines have been madewith rotary cutter bars or drums located behind. the rotary cutter armsin approximately the same position as above mentioned upper and lowerflights of a trim chain. In general, such rotary cutter bars 3,409,331Patented Nov. 5, 1968 or drums are made of metal stock of round crosssection with a plurality of lugs or socket members welded thereto. Inorder to obtain sufficient strength, the diameter of the round stockfrom which the cutter bar is made must be relatively large, and the lugswhich are affixed about its periphery must be of relatively large andheavy construction. This results in a large bit circle (i.e., the circledescribed by the cutting tip of the bit). The larger'the'bit circle, themore work the cutter bars must perform and the more power is required torotate them. In order to reduce the bit circle, bits of shorter gaugehave been used but this tends to interfere with the flow of material cutby the cutter bar. The cutter bits are generally of the replaceabletype, having shanks entering into perforations in the socket members.These shank receiving perforations are open at one end only, and anaccumulation of cuttings and fines therein often makes bit replacementdiflicult.

Accordingly, the present invention teaches the provision of improvedcutter bars having recessed lugs or socket members, whereby the lugs aremechanically held in addition to Welding, and the lugs themselves may beof a lighter construction. Furthermore, the lugs or socket members haveshank receiving perforations therein which are not blind. The rotarycutter bars of the present invention are such that a smaller bit circlecan be achieved and at the same time bits of longer gauge may be usedwhereby the flow of cut material is improved. It is thus possible, forexample, to provide a rotary cutter bar utilizing the same cutter bitsas are used on other portions of the continuous mining machine. Therotary cutter bars of the present invention are characterized by greatstrength, relatively small bit circles and require a minimum of powerfor their operation. The cutter bits may be easily and rapidly changed,and the lugs may be adapted to utilize a particular type of resilientcutter bit retaining means, as described hereinafter.

SUMMARY OF THE INVENTION The rotary cutter bars of the present inventionare in tended for use in various types of well known continuous miningmachines. The rotary cutter bars are intended to be supported at theirends and caused to rotate against the material being mined so as to cuttherethrough.

In one embodiment, the cutter bar comprises an elongated cylindricalelement provided with a plurality of longitudinally extending groovesspaced about its periphery. Each groove provides a pair of spacedsurfaces between which lugs or socket members are located. The lugs areheld in place by any suitable means such as welding or the like. Eachlug is provided with a perforation adapted to receive the shank of acutter bit.

A second embodiment of the rotary cutter bar of the present inventioncomprises a first elongated plate and second and third elongated platesaflixed to opposite sides of the first plate. The three plates form anelongated ele ment having an X-shaped cross sectional configuration, thelegs of which are of equal length. The spaces between adjacent legscomprise V-shaped notches extending the length of the rotary cutter bar.Lug members are located in the V-shaped notches and are aflixed to thesurfaces of adjacent legs. It is within the scope of the invention, toform rotary cutter bars, in similar manner, with three or more elongatedplates so as to form three or more V-shaped notches.

In a third embodiment, a plurality of elongated members are heldtogether in spaced relationship by lugs located between and afiixed toadjacent surfaces of the elongated members.

The lugs of any of the embodiments of the present invention may bearranged in any suitable manner. They are preferably arranged in twohelices extending from the BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is asemi-diagrammatic front elevation of a continuous mining machineillustrating the various cutting means'thereon. v

FIG. 2 is a diagrammatic representation of the cuts made by theinterdigitating rotary cutter arms and the rotary cutter bars of themining machine of FIG. 1 and illustrating the cores left thereby.

FIG. 2a is a diagrammatic representation of the cuts made by a miningmachine having two interdigitating rotary cutter arms and rotary cutterbars, and illustrating the cores left thereby.

FIG. 3 is a fragmentary elevational view of the rotary cutter bar of thepresent invention.

FIG. 4 is a cross sectional view taken along the section line 4-4 ofFIG. 3 and illustrates a cutter bit positioned in one of the lugs.

FIG. 5 is a diagram showing the relative placement of the cutterbit-socket member assemblies on the rotary cutter bar of the presentinvention.

FIG. 6 is an end elevation of the cutter bar of the present invention asseen from the left in FIG. 3.

FIG. 7 is an end elevation of the tongue of the driving means for therotary cutter bar of the present invention.

FIG. 8 is a fragmentary elevation of a second embodiment of the cutterbar of the present invention.

FIG. 9 is a cross sectional view taken along the section line 99 of FIG.8.

FIG. 10 is a perspective view of a tool used in the installation andremoval of resilient cutter bit retaining means in the rotary cutter barof the present invention.

FIG. 11 is a cross sectional view similar to FIG. 4 and showing the useof a different type of cutter bit-socket member assembly.

FIG. 12 is a plan view of a type of resilient retaining means which maybe used in association with the cutter bar of the present invention.

FIG. 13 is a fragmentary elevation of a third embodiment of the cutterbar of the present invention.

FIG. 14 is an end elevation of the cutter bar of FIG. 13 illustrating inbroken lines the position of the tongue of the driving means for therotary cutter bar.

FIG. 15 is a cross sectional view of the rotary cutter bar of FIG. 13,showing a cutter bit and retaining means positioned in one of the socketmembers.

FIG. 16 is a cross sectional view, similar to FIG. 15, and showing theuse of a different type of cutter bit-socket member assembly.

FIG. 17 is a fragmentary perspective view of the cutter bar of FIG. 13illustrating the use of another type of socket member.

DESCRIPTION OF THE PREFERRED EMBODIMENTS It will be understood by oneskilled in the art that the improved means of the present invention maybe employed with various types of well known continuous mining machines.For the purpose of an exemplary showing these means are described withreference to that type of continuous mining machine characterized byinterdigitating rotary cutter arms. FIG. 1 is a diagrammatic front orhead end view of a continuous mining machine generally indicated at 1.Rotary cutting means 2, 3 and 4 are provided with interdigitating cutterarms 2a, 3a and 4a respectively. These arms have a plurality of cuttingmeans indicated at 2b, 3b and 4b respectively. The cutting meansgenerally consist of socket members of lugs attached to the arms andadapted to holdcutter. bits which can be replaced when worn, all as iswell known in the art.

The machine 1 is also provided with upper and lower rotary cutter bars 5and 6.- One end of each of the rotary cutter bars is supported bysuitable bearing-means not shown. The other. endof .each cutter bar; isjoined to means for imparting rotation to the cutter bar. The rotationimparting means are diagrammatically indicated at 5a and 6a. i

The central portionof the machine'is provided with conveyor meansgenerally indicated at 7 for carrying coal away from the cut toanother'con'veyor means (not shown) located behind the machine.

FIG. 2 is a diagrammatic representation of the various cuts made by themachine of FIG. 1 in the face of the material being mined. The series ofconcentric circles generally indicated at 8, 9 and 10 illustrate-thecuts made by the cutter bits mounted in socket members on the rotatingcutter arms 2a, 3a and 4a respectively. It will be noted that theoutermost ones of the concentric circles 8, 9 and 10 overlap in theareas generally indicated at 11 and 11a. The horizontal band 12represents the cut made by the upper rotating cutter bar 5. Thehorizontal band 13 represents the cut made by the lower rotary cutterbar 6. It will be noted that the cutting actions thus far describedleave cores generally indicated at 14 which will be broken off andremoved by additional means on the machine (not shown). I

FIG. 2a is a diagrammatic representation of the various cuts made by amining machine similar to that of FIG. 1, but having only twointerdigitating rotary cutter arms. The series of concentric circlesgenerally indicated at 15 and 16 represent the cuts made by the twointerdigitating rotary cutter arms. The outermost ones of the circles 15and 16 overlap as at 17. Cutter bars located behind the rotary cutterarms make upper and'lower cuts 18 and 18a, leaving upper and lower cores19 and 19a. Means (not shown) are provided on the machine to break upthe cores 19 and 19a.

It is the rotary cutter bars making the cuts 12 and 13 in FIG. 2 or 18and 18a in FIG. 2a with which the present invention is concerned, and itwill be understood that the cutter bars such as 5 and 6 in FIG. 2 can besubstantially identical in their construction.

One embodiment of the rotary cutter bar of the present invention isshown in FIGS. 3-6. The cutter bar itself (generally indicated at 20) ismade up of an elongated piece of metallic round stock. The elongatedelement "21 is provided with a plurality of longitudinally extendinggrooves spaced about its periphery. While the number of such groovesdoes not constitute a limitation on the present invention, it has beenfound satisfactory to provide four of them as shown at 22-25. Forpurposes of an exemplary showing the grooves 22-25 are illustrated asbeing substantially rectangular in cross section, presenting parallelspaced side surfaces slightly relieved at their outer edges as at22a-25a. The grooves 22-25 are adapted to receive a plurality ofidentical socket members or lugs. Each lug 26 is of rectangularconfiguration having a shank receiving perforation 26a. As shown in FIG.4, the shank 27a of a cutter bit 27 is adapted to extend into the lugperforation 26a and to be held therein by means described hereinafter.The lugs 26 are so dimensioned as to have a relatively close fit withinthe grooves 22-25, with only a small portion of each lug extendingbeyond the periphery of the elongated element 21. The lugs are held inplace by any suitable means such as welds 28 preferably at the positionsof the reliefs 22a-25a.

It will be understood by one skilled in the art that the reliefs 22a25ado not constitute a limitation on the present invention and that thegrooves 22-25 may have any appropriate cross sectional configuration toaccommodate a lug of any particular external shape.

FIG. Sis a flat diagram indicating the relative positions of thelug-cutter bit assemblies. As indicated, the four longitudinal linesrepresent the grooves 22-25, andthe dots 29 represent the lug-cutter bitassemblies. While the arrangement of the cutter bit-lug assemblies isnot so limited, it is preferred that they be arranged about theperiphery of the elongated element 21 in the form of two helicesextending from the ends of the element 21 to its center, the helicesbeing of opposite hand. Such an arrangement tends to direct the flow ofcut material toward the center of the mining machine to the conveyor 7.

It will be noted from FIGS. 3 and 4 that the element 21 has a pluralityof transverse perforations 30 passing therethrough and coaxial with theshank receiving perforations 26a in each of the lug members 26. In thisway, the shank receiving perforations are not blind, and the cutter bits27 may be replaced quickly and easily without the difficulties normallyencountered when the shank receiving perforations 26a are blind andfilled with fines and other foreign material. I

The bits 27 may be held in place in the lugs or socket members by anysuitable means. An advantage of the structure of the present inventionlies in the fact that a resilient bit holding means may be used similarto that shown in US. Letters Patent No. 2,965,365 dated Dec. 20, 1960,in the name of the present inventor. To this end, each lug 26 isprovided with a transverse hole 26b which partially intersects the shankreceiving perforation 26a. The hole 26b is adapted to receive aresilient holding device (generally indicated at 31 in FIG. 12)comprising a metallic rod 32 encased in a body of resilient substance33. The resilient body is cut away as at 34 to expose that portion ofthe rod 32 which traverses the shank receiving perforation 26a. Theresilient retainer 31 may, if desired, be provided with a cage-likeelement 35 of metal which forms, inter alia, a key. When such a cagelikeelement or key is provided, the hole 26b will be broached to accept thekey as hitherto understood in the art. When a resilient retainer of thetype described (or any type which is positioned within the lug by meansof a transverse hole therein) is used, the lugs 26 in any one of thegrooves 22-25 will be spaced from each other by a distance sufficient topermit insertion of the retainer in the transverse hole from at leastone side of the lug.

The rear portion of the shank 27a of the cutter bit 27 has a relievedportion 27b and a notch 270. As described in the above mentioned patent,when the bit shank 27a is inserted in the shank receiving perforation26a, the relieved portion 27b of the bit shank will depress the metalrod 32 until it can enter the shank groove 270, after which the bitshank will be firmly held in the socket member. The cutter bit can-beremoved for replacement purposes by means of a suitable prying toolacting upon the head thereof. The notch 27c is so configured as to causethe pin 32 to be depressed until it is dislodged from the notch 270.

FIG. illustrates an exemplary tool for use in the insertion and removalof a resilient retaining means of the type shown in FIG. 12. The tool,generally indicated at 36, comprises a flat elongated handle 37 havingends 37a and 37b. Near the end 37b, a laterally extending lug 38 isaffixed to the handle 37 by any suitable means such as Welding or thelike. The lug 38 may be cylindrical in configuration and of a diametersuch that it may be received in the transverse hole 26b of a lug 26.When the lugs in any given one of the grooves 22-25 are spaced from eachother as described above, sufficient room is thereby provided to enablea resilient retainer 31 to be started in a transverse lug hole 26b byhand. To illustrate, it will be noted that the lug indicated at 26' inFIG. 3 is located in the groove 25 in the element 21. The groove 25 isunoccupied on either side of the lug 26' as at 25a and 25b. Thus, aresilient retainer 31 may be started by hand in the transverse hole 26b,the remainder of the resilient retainer extending into the space 25a.The end 37a of the tool 36 may then be inserted in the space 25a '6against the resilient retainer. Lateral blows to the. tool handle 37will cause the retainer 31 to be driven home.

When the resilient retainer in the lug 26 is to be removed, the end 37bof the tool 36 may be placed in the space 25a with the free end of thelug 38 positioned against the end of the resilient retainer. Lateralblows on the handle 37 will cause the lug 38 to enter the transversehole 26b and will cause the resilient retainer to be driven out of thetransverse hole 26b into the space 25b in the groove 25.

The ends of the elongated elements 21 may have adapters 39 and 40permanently affixed thereto. The adapters 39 and 40 constitute means forreceiving the ends of supporting shafts, one at least of which impartsrotation to the cutter bar. The adapter 39 is clearly shown in FIGS. 3and 6, and it will be understood that the adapter 40 is a mirror imagethereof. While not so limited, the adapter may have about its peripherya series of fiat surfaces located adjacent to and equal in number to thenumber of longitudinal grooves in the element 21. Since, in theexemplary embodiment, the cutter bar is illustrated as having fourgrooves 22-25, the adapter has four fiat surfaces 41-44. These surfaceslie in the same planes defined by the upper surfaces of the lugs 26 inthe grooves 22-25 respectively. The adapter also has a centralperforation 45 of noncircular cross section and coaxial with the axis ofthe elongated element 21. The perforation 45 is adapted to receive thetongue or shaft of a driving element such as those shown at 10 and 11 inFIG. 1. The adapter 40 is provided with a similar perforation, adaptedto receive a shaft or tongue cooperating with the supporting bearingmeans on the mining machine at the other end of the cutter bar. The face39a of the adapter, to which the end of the elongated member 21 ispermanently aflixed, has formed therein appropriately shaped recesses toreceive one-half of the endmost lug in the groove 22, and to formone-half of the transverse perforation associated therewith. Theserecesses are generally indicated at 46 in FIGS. 3 and 6. The adapter isalso provided with perforations 47, 48 and 49 extending respectivelyfrom the srufaces 42, 43 and 44 to the central perforation 45. Theperforations 47, 48 and 49 are appropriately spaced and configured toserve as shank receiving perforations for additional cutter bits, sothat the cutter bar is provided with cutter bits throughout its lengthincluding the adapters 39 and 40.

As shown in FIGS. 3 and 6, the adapter has a series of transverse holes50 53. The hole 50 communicates with the transverse hole 26b in theaforementioned endmost lug 26 in the groove 22. The remaining holes 51,52 and 53 partially intersect the perforations 47, 48 and 49 in theadapter and are configured to receive resilient retaining means 31therefor. It will be noted, particularly from FIG. 3, that the holes 51,52 and 53 in the areas of the perforations 47, 48 and 49 respectivelyare of substantially the same size and configuration as the transverseholes 26b in the lugs 26. The remainder of each of the holes 51, 52 and53 are of an enlarged diameter whereby insertion and removal ofresilient retaining means therein is rendered easier.

While the length and diameter of the elongated element 21 do notconstitute a limitation on the present invention, it will be understoodfrom the foregoing description that by virtue of the recessing of thelugs 26 in grooves in the element 21, a cutter bar having a desired bitcircle may be provided using conventional cutter bits 27 andcharacterized by great strength. The recessing of the lugs 26 alsopermits them to be of lighter construction and less welding is requiredto affix them to the element 21 since they are mechanically held in thelongitudinal grooves 22- 25. The use of conventional bits having arelatively long gauge produces coarser cuttings, aids in the flow of cutmaterial toward the mining machine conveyor 7, and facilitates thefeeding of the mining machine into the face of the material being cut.The cutter bar of the present invention has, by virtue of its structure,the further advantage of the capability of using the resilient retainerssuch as those of the above mentioned patent which makes bit replacementa relatively quick and simple process of the knock-in, pry-out type.

The cutter bars of the present invention may be made of any desireddiameter, and the size of the cutter bars does not constitute alimitation. However, as a non-limiting example, heretofore it has beencommon when a cutter bar having a bit circle of twelve inches wasdesired to start out with an elongated piece of metallic round stock ofsix inch diameter to which lugs were welded. It was often necessary toprovide specially sized cutter bits of shorter gauge in order to attainthe twelve inch bit circle. In a cutter bar of the present invention,having a bit circle of twelve inches, the element 21 may be made ofeight inch diameter round stock, and conventional cutter bits may beused, being the same bits as are used elsewhere on the cutting elementsof the mining machine.

For a given strength factor, the structure of the present inventionpermits the manufacture of a rotary cutting bar having a bit circlesmaller than heretofore possible, and still utilizing conventionalcutter bits. It will be evident from FIG. 6 that if the cutter barillustrated were of a smaller diameter, and adapted to use the sameconventional bits 27, the bit shanks 27a would extend partially into thecentral perforation 45 of the adapter, FIG. 7 is an end elevation of thetongue or shaft 54 which is received in the adapter perforation 45. Ifthe diameter of the cutter bar is such that the cutter bit shanks extendinto the perforation 45, the shaft 54 may be provided with anappropriate number of longitudinal grooves (indicated in dotted lines at55-58) to accommodate them.

FIG. 11 is a cross sectional view (similar to FIG. 4) of the rotarycutter bar of the present invention illustrating the use of a lug-cutterbit assembly of the type described in the copending case of the sameinventor, Serial No. 611,513, filed Dec. 19, 1966, and entitled, cutterbits and means for mounting them.

In FIG. 11 like parts have been given like index numerals. The elongatedelement 21 again has longitudinally extending grooves 22-25 relieved attheir outer edges as at 22a-25a. The element 21 may be substantiallyidentical to that shown in FIG. 4 except that there is in thisembodiment no need for the transverse perforations 30.

In this embodiment lugs 59 are so configured as to have a relativelyclose fit in the grooves 22-25, and are permanently affixed therein asby welding at 22a-25a. As described in the above identified copendingapplication, the lugs 59 have a shank receiving perforation 60 and anabutment means 61 in association with the rear face of the lug. Asurface portion of the abutment means 61 extends across and parallel tothe rear surface of the lug. The abutment surface also extendstransverse the axis of the shank receiving perforation and is spacedfrom the rearward opening of the perforation. The shank receivingperforation 60 may be a simple cylindrical bore. As illustrated, acutter bit holder 62 having a cylindrical shank of substantially thesame diameter throughout its length is adapted to be received within theperforation 60. The rearward end of the cutter bit holder will contactthe abutment surface of the element 61 which serves as a gaugedetermining means for the shank. The forward end of the cutter bitholder has a conical cutter bit 63 removably afiixed thereto. As isdescribed in the copending application, a cutter bit having acylindrical shank and a conical nose may be used instead of the cutterbit-cutter bit holder assembly illustrated in FIG. 11. As is furtherdescribed, a number of different types of retaining means (not shown),including the type described above, may be provided for preventing theshank of the cutter bit or cutter bit holder and bit assembly from beingremoved from the lug perforation 60.

FIGS. 8 and 9 show another embodiment of the rotary cutter bar of thepresent invention. In this instance, the

elongated member (generally indicated at 64) which supports thelug-cutter bit assemblies, comprises a plate 65 and additional plates 66and 67 affixed to opposite sides of the plate 65 along its axis. As ismost clearly shown in FIG. 9, the elongated element 64 has a X-shapedcross sectional configuration, the legs of which are of equal length.The spaces between adjacent legs comprise V-shaped notches or slots68-71 which extend the full length of the element 64. The notches 68-71are adapted to receive lugs 72, which are similar to the lugs 26 ofFIGS. 3 and 4, but are relieved as at 72a and 72b so as to fit properlyWithin the notches. The lugs 72 may be affixed to the element 64 in anysuitable manner such as by welds 73. The relative placement of the lugs72 on the element 64 may be substantially the same as the placement ofthe lugs 26 on the element 20 (see FIGS. 3 and 5). The distance betweenadjacent lugs in any one of the notches 68-71 may be as above described.Each lug 72 may have a shank receiving perforation 74 and a transversehole 75 similar to the shank receiving perforation 26a and transversehole 26b of the lugs 26 of FIGS. 3 and 4. The lugs 72 (while not solimited) may use the same cutter bit and resilient retaining means asdescribed with respect to FIGS. 3 and 4, and like parts have been givenlike index numerals. The manner in which the bits 27 may be inserted andremoved from the perforation 74 of the lug 72 is the same as describedabove, and the same is true for the insertion and removal of resilientretaining means 31. Insertion and removal of the resilient retainingmeans 31 may be accomplished by means of the tool 36 as described above.

The elongated element 64 will be provided with a plurality of transverseperforations 76 at the position of the shank receiving perforation 74 ofeach of the lugs 72. The transverse perforations 76 serve the samepurpose as the transverse perforations 30 in the elongated element 21.The rotary cutter bar of FIGS. 8 and 9 may be provided with adapterssimilar to those shown at 39 and 40 in FIGS. 3 and 6. As illustrated inFIG. 8, however, more simplified adapters 77 and 78 may also be used.The adapters 77 and 78 are identical and comprise respectively metallicdiscs 77a and 78a permanently afiixed to the elongated element 64 andhaving integral shafts 77b and 78b. One of the shafts 77b or 78b will besupported in suitable bearing means, while the other will be coupled tosuitable drive means.

It will be understood by one skilled in the art that the embodiment ofthe rotary cutter bar of the present invention shown in FIGS. 8 and 9will have all of the advantages described with respect to the embodimentof FIGS. 3-6. It will be further understood that the lugcutter bitassemblies of FIG. 11 may also be used on the cutter bar of FIGS. 8 and9 if the lugs 59 are provided with suitable reliefs to make them conformproperly to V-shaped notches 68-71.

It is within the scope of the invention to form a rotary cutter barsimilar to that shown in FIGS. 8 and 9 but having a Y-shaped crosssectional configuration. In this instance, the plates 65, 66 and 67 willbe of equal width and will be joined together in such a way that alongitudinal edge of each plate will lie substantially along the longaxis of the cutter bar. In addition, more than three elongated platesmay be so joined, or more than one plate (such as plate 66 or 67 in FIG.9) may be joined to the sides of plate 65 so as to form a rotary cutterbar having any desired number of longitudinaly extending V-shapednotches for the receipt of lugs.

FIGS. 13-16 illustrate a third embodiment of the rotary cutter bar ofthe present invention. In this instance, the rotary cutter bar comprisesa plurality of elongated structural members joined together andmaintained in spaced relationship with respect to each other by aplurality of lugs. While not so limited, for purposes of an exemplaryshowing this embodiment is illustrated as comprising four elongatedstructural members 79-82. The structural members 79-82 may have arectangular cross section, and are joined together by a plurality oflugs 83. This is most clearly shown in the cross sectional view of FIG.15.

The lugs 83 may be of any suitable type, and may be similar to the lugs26 of FIGS. 3 and 4, and substantially identical to lugs 72 of FIG. 9.The bottom corners 83a and 83b of the lugs will be relieved so as toconform to the surfaces of adjacent ones of the structural members79-82.

The lugs and the structural members may be joined in any suitablemanner, such as by welds 84, to form a unitary structure. Again, therelative placement of the lugs 83 with respect to each other may takeany suitable form, and preferably may be substantially the same as theplacement of the lugs 26 on the element 20 (see FIGS. 3 and 5).

The distance between adjacent ones of the lugs 83, located betweenadjacent ones of the structural members 79-82, may be the same asdescribed above with respect to FIGS. 3-6. Each lug 83 may have a shankreceiving perforation 85 and a transverse hole 86, similar to the shankreceiving perforation 26a and transverse hole 26b of the lugs 26 ofFIGS. 3 and 4. The lugs 83 (while not so limited) may use the samecutter bit and resilient retaining means as described with respect toFIGS. 3 and 4. This is illustrated in FIG. 15, and like parts have beengiven like index numerals.

The manner in which the bits 27 may be inserted and removed from theperforations 85 of the lugs 83 is the same as described above, and thesame is true for the insertion and removal of the resilient retainingmeans 31. Again, insertion and removal of the resilient retaining meansmay be accomplished by a tool such as that described with respect toFIG. 10.

While the invention is not intended to be so limited, it is oftendesirable to provide a lug between each of the structural members 79-82at the ends of the cutter bar. If the lugs are uniformly arranged aboutthe periphery of the assembly, no difiiculty is encountered. When,however, the lugs are affixed between the structural members in ahelical fashion, the arrangement of the lugs at the ends of the rotarycutter bar will be as illustrated in FIGS. 13 and 14.

In such an instance, one lug 83, similar to the lugs used throughout thelength of the cutter bar, will be located at the end thereof. The nextlug 83a will have to be extended (as shown in FIG. 13) in order tocontinue the helical pattern. The remaining two lugs 83b and 830 will bedummy lugs. The dummy lugs 83b and 83c will not have a shank receivingperforation and will not be intended to carry a cutter bit. These lastmentioned lugs will, however, have transverse perforations 87 by whichaccess may be had to the transverse perforations in adjacent lugs. Inother words, the perforations 87 are similar in purpose to the hole 50in the adapter 39 of FIGS. 3 and 6.

The rotary cutter bar of FIGS. 13-16 may be provided with any suitabletype of adapter such as those shown, for example, at 77 and 78 in FIG.8. One advantage of the construction of the embodiment of FIGS. 13-16,however, is that no adapter need be provided. It will be noted from FIG.14, that the structural members 79-82 define a four-sided hole locatedcentrally of and extending throughout thelength of the rotary cutterbar. The hole is generally indicated at 88. The hole 88 is adapted toreceive the tongue or shaft of a bearing means or a driving element,indicated in dotted lines at 89. Similarly, shaft elements (not shown)may be inserted into the hole 88 at both ends of the rotary cutter barand may be affixed therein 'by any suitable means such as Welding or thelike. Such shaft elements may be adapted to connect with a bearing meansat one end of the cutter bar and a driving element at the other end ofthe cutter bar.

Shouldv a cutter bit 27 be used, having a shank 27a of such length as tointerfere with a shaft in the perforation 88, the shaft may beappropriately relieved in much the same manner as described with respectto FIG. 7. In this instance, however, the edges of the shaft rather thanthe side surfaces would be relieved.

FIG. 16 is a cross sectional view of the rotary cutter bar of FIG. 13illustrating the use of the lug-cutter bit assembly of the abovementioned copending application. The lug-cutter bit assemblies aresubstantially identical to those shown in FIG. 11 and like parts havebeen given like index numerals. It will be noted that the lugs 59 areprovided with suitable reliefs 59a to -make them conform to the surfacesof adjacent ones of the structural elements 79-82. The lugs will bejoined to the structural elements by any suitable means such as welds90.

In the embodiment of FIG. 16, when it is desired to have four lugelements at the ends of the cutter bar, one

I of the lugs may be the same as those used throughout the length of thecutter bar. Two of the lugs may be dummy lugs, and the fourth lugs maybe extended in Width. In other words, the arrangement will 'besubstantially the same as that described with respect to FIGS. 13 and14.

The rotary cutter bar of FIGS. 13-16 will have all of the advantagesdescribed with respect to the embodiment of FIG. 3 and the embodiment ofFIG. 8. In addition, the cutter bar of FIGS. 13-16 requires no drilling,planing or the like in its assembly. It is within the scope of theinvention to make the lugs of high grade alloy material, to insureexcellent strength characteristics of the cutter bar.

FIG. 17 is a fragmentary perspective view of a cutter bar of the typeshown in FIGS. 13-16 and illustrates another type of lug or socketmember. The lug, generally indicated at 91, is characterized by atransverse, U-shaped cross sectional configuration. The U-shaped crosssection is the result of a notch 92 in one face of the lug extendingfrom the lug top 93 through the lug bottom 94. The notched face 95 ofthe lug is affixed by welding or the like to the structural member 79 ofthe rotary cutter bar. The opposite face 96 of the lug is affixed to theadjacent structural member 80.

As will be evident from FIG. 17, when the lug 91 is positioned betweenthe structural elements 79 and 80, the side surface 791: of thestructural element 79 will enclose the notch 92 so as to form a shankreceiving perforation into which the shank of a cutter bit may beinserted. The lug 91 may also have a transverse hole 97, partiallyintersecting the notch 92 and adapted to receive a resilient retainingmeans for maintaining the shank of a cutter bit in the shank receivingnotch or perforation 92. The retaining means may be of any suitable typeincluding that described with respect to FIG. 12.

It will be understood by one skilled in the art that the lug 91 may beused in any of the embodiments of the rotary cutter bar of the presentinvention. For example, the lug 91 may be suitably configured for use incutter bars of the type shown in FIGS. 3 and 8.

Since the lug 91 utilizes a part of the cutter bar itself to completethe shank receiving perforation, the lug may be made smaller and stillaccommodate conventional cutter bit means. As a result, use of lugs suchas lug 91 enables the achievement of a smaller bit circle, or theprovision of more longitudinally extending lug receiving notches in thecutter bar, or both.

Modifications may be made in the invention without departing from thespirit of it. For example, the elongated element 21 of the cutter bar ofFIGS. 3 and 4 may have the grooves 22-25 so machined therein as tofollow helical paths about its periphery. Furthermore, the elongatedelement 21 of FIGS. 3 and 4 may be made up of two or more parts. Theseparts may be Welded end-toend to form a unitary cutter bar. In being'welded end-toend the various parts may be turned through a small anglewith respect to each other so that the longitudinal grooves of the partswill lie in different peripheral positions.

It is within the scope of the invention to provide the adapters 39 and40 of FIGS. 3 and 6 with integral shaft means, eliminating the centralshaft receiving perforation 45. Alternatively, the embodiment shown inFIG. 3 may be provided with adapters of the type shown at 77 and 78 inFIG. 8.

The embodiments of the invention in which an exclusive property orpriviledge is claimed are defined as follows:

1. A rotary cutter bar for a continuous mining machine and the like,having a longitudinally extending axis of rotation and comprising atleast one elongated body member providing a plurality of pairs of spacedsurfaces extending the length thereof, a plurality of lugs being locatedin spaced relationship to each other between the spaced surfaces of eachof said pairs and affixed therebetween to said body member, each of saidlugs having means for the attachment of a cutter bit thereto.

2. The structure claimed in claim 1 including a plurality of elongatedbody elements spaced equidistant from each other and equidistant fromsaid axis, each of said elements having two side surfaces, said pairs ofspaced surfaces comprising a side surface of each of two adjacent onesof said body elements, said lugs located between adjacent ones of saidbody elements and affixed to said spaced surfaces of said pairs wherebyto join said body elements together.

3. The structure claimed in claim 1 wherein said lugs are spaced aboutthe periphery of said elongated body member in such a way as to form twohelices of opposite hand starting from the ends of said elongated bodyand meeting at the middle thereof.

4. The structure claimed in claim 1 including means affixed to the endsof said elongated body adapted to receive driving and supporting shaftsassociated with the mining machine and each the like, said means havinghave a central shaft receiving perforation, said perforation beingcoaxial with said axis of rotation.

5. The structure claimed in claim 1 including means affixed to the endsof said elongated body, each of said means having an outwardly extendingshaft coaxial with said axis of rotation.

6. The structure claimed in claim 1 wherein each of said lugs comprisesa body having a pair of surfaces lying adjacent said spaced surfacesbetween which said lug is located, one of said lug surfaces having anotch therein, said notch and a portion of the adjacent one of saidspaced surfaces forming a perforation adapted to receive the shank of acutter bit means.

7. The structure claimed in claim 1 wherein said elongated body membercomprises a cylindrical element, said cylindrical element having aplurality of grooves extending inwardly from the periphery thereof andextending the length thereof, said grooves forming said pairs of spacedsurfaces, said lngs being ailixed to said body member partially withinsaid grooves, said lugs being proportioned with respect to said groovesas to be in part at least mechanically held therein.

8. The structure claimed in claim 7 wherein each of said lugs hasperforation adapted to receive the shank of a cutter bit means, saidshank receiving perforation extending through said lug and beingunobstructed at both ends, said elongated body member having a pluralityof transverse holes coaxial with the shank receiving perforations ofsaid lugs.

9. The structure claimed in claim 1 wherein said elongated body memberhas an X-shaped cross section, the outermost ends of the legs of saidX-shaped cross section being equidistant from said axis of rotation,each of said legs having two side surfaces, said pairs of spacedsurfaces comprising a side surface of each of two adjacent ones of saidlegs of said X-shaped cross section, said lugs being located between andaffixed to said spaced surfaces of said pairs.

10. The structure claimed in claim 9 wherein each of said lugs has aperforation adapated to receive the shank of a cutter bit means, saidshank receiving perforation extending through said lug and beingunobstructed at both ends, said elongated body member having a pluralityof transverse holes coaxial with the shank receiving perforation of saidlugs.

11. The structure claimed in claim 1 including a plurality of elongatedbody members joined together to form a unitary structure having aplurality of longitudinally extending notches therein, each of saidnotches having surfaces comprising one Of said pairs of spaced surfaces.

12. The structure claimed in claim 11 wherein said lugs located betweensaid spaced surfaces of said pairs are affixed to said surfaces.

13. The structure claimed in claim 1 including a plurality of cutter bitmeans, each of said cutter bit means having a shank, each of said shankslocated within a shank receiving perforation of one of said lugs, andmeans for retaining said shanks in said perforations.

14. The structure claimed in claim 13 wherein said retaining meanscomprise resilient retaining means whereby the engagement of said shanksin said perforations may be of the knock-in, pry-out type.

15. The structure claimed in claim 13 wherein the shank of each of saidcutter bit means has a notch therein, each of said lugs has a holeextending transversely of said shank receiving perforation andintersecting it, said retaining means comprising a resilient bodyextending in said hole, said body having an engagement means located atleast partially within said perforation, said engagement means beingresiliently displaceable transversely of the axis of said perforationand being engageable and disengaga-ble with said notch in said shank.

16. The structure claimed in claim 13 wherein the shank of each of saidcutter bit means has a notch therein, each of said lugs has a holeextending transversely of said shank receiving perforation andintersecting it, said retaining means comprising a pin extending in saidhole across said perforation so that at least a part of the centralportion of said pin is located within said perforation, the end portionsof said pin located beyond said perforation being mounted within saidhole in surrounding bodies of rubbery resilient substance so that thecentral portion of said pin is resiliently displaceable transversely ofits axis within said perforation and is engageable and disengagable withsaid notch in said shank, said lugs located between each of said pairsof spaced surfaces being spaced from each other by a distance greaterthan the length of said retaining means, and said elongated body havinga plurality of transverse holes coaxial with said shank receivingperforation of said lugs.

17. The structure claimed in claim 1 wherein each of said lugs has aperforation adapted to receive the shank of a cutter bit means, saidshank receiving perforation extending through a part at least of saidlug and being unobstructed at both ends.

18. The structure claimed in claim 17 wherein said elongated body memberhas a plurality of transverse holes coaxial with said shank receivingperforations of said lugs.

19. The structure claimed in claim 17 wherein each of said lugs has ahole extending transversely of said shank receiving perforation andintersecting it, said lugs located between a given one of said pairs ofsurfaces being spaced from each other by a distance sufficent to permitaccess to said transverse holes.

20. The structure claimed in claim 17 wherein each of said lugscomprises a body portion and an abutment portion, said body portionhaving a forward surface and a rearward surface, said shank receivingperforation extending through said body portion and forming openings insaid forward and rearward surfaces, said abutment portion being spacedrearwardly of said body portion and overlying a part at least of saidshank receiving perf- 13 oration, said abutment portion having anabutment surface thereon for the end of the shank 01f a cutter bitmeans, said abutment surface facing said opening in said rearwardsurface of said body portion and lying perpendicular to the axis 045said perforation.

21. The structure claimed in claim 17 including means in associationwith each of said lugs for retaining the shank of a cutter bit means insaid shank receiving perforation.

22. The structure claimed in claim 17 including means affixed to saidcutter bar adapted to receive rotatable shafts associated with themining machine and the like, said means comprising adapaters havingbodies with end surfaces, one end surface of each adapter beingpermanently afiixed to an end of said elongated body member, eachadapter having a central shaft receiving perforation coaxial with theaxis of said elongated body member, the

References Cited UNITED STATES PATENTS 1,473,498 11/1923 Morgan 29989 X2,700,189 1/1955 Mick 29989 X 8,823,023 2/1958 "Hlinsky 29987 X FOREIGNPATENTS 856,226 12/ 1960 Great Britain.

ERNEST R. PURSER, Primary Examiner.

